Set Appliance State:
Mains Power Off
Set Multimeter to AC Volts 
DHW Demand
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Press Reset to cancel purge cycle countdown.
Measure the voltage between the flame sense electrode connection and a suitable Earth.
Allow ignition sequence to commence.
As the burner ignites the voltage should decrease from 91 VAC to 81 VAC (approximately a 10 VAC drop).
Measure the voltage between the flame sense electrode connection and a suitable Earth.
Allow ignition sequence to commence.
As the burner ignites the voltage should decrease from 91 VAC to 81 VAC (approximately a 10 VAC drop).
Isolate as per TOPs P4
and refit as necessary